High-concentration particle concentrate, powder, preparing method of high-concentration particle concentrate, and preparing method of powder

ABSTRACT

A powder preparing device has a filtering device which processes CMP waste water and a vacuum dry-freezing device which dries a slurry which is concentrated to a high concentration by the filtering device. A membrane module in which at least one gel filtering film in which a gel layer is formed on a surface of a filtering membrane having a pore size of 0.25 μm is provided is placed within the filtering device. A pump sucks waste water from within the gel filtering membrane of the membrane module. The high-concentration slurry obtained by the filtering device may be supplied for various uses without further processing, or a powder may be obtained by transporting the high-concentration slurry to the vacuum dry-freezing device using a transporting pump and applying a drying process.

CROSS-REFERENCE TO RELATED APPLICATIONS

The entire disclosure of Japanese Patent Applications No. 2004-97061,2004-97064 and 2005-80614 including specification, claims, drawings andabstract is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high-concentration particleconcentrate, a method of preparing a high-concentration particleconcentrate, a fine particle, and a method of preparing a fine particle.

2. Description of the Related Art

Commonly, a thin substrate such as a silicon substrate and a wafer usedin a semiconductor manufacturing is polished and planarized using a CMP(Chemical Mechanical Polishing) system. In general, with a CMP system,because it is possible to completely planarize a layer to be exposed ina manufacturing process of a semiconductor device, reduce load of theexposure technology, and to stabilize yield, CMP systems have becomenecessary for, for example, planarizing an interlayer insulting film anda BPSG film, a shallow trench isolation, etc.

In a manufacturing process of a semiconductor device, as a CMP polisherfor planarizing an inorganic insulating film layer such as a siliconoxide insulating film which is formed through plasma CVD (Chemical VaporDeposition), a low-pressure CVD, etc., a material such as, for example,cerium oxide (ceria; CeO₂), a silica particle, an alumina particle, anda titania (titanium oxide; TiO₂) particle is used. The polishers aretypically dispersed into a solvent such as water, and a chemicalreaction catalyst such as potassium hydroxide and a dispersant such asan organic high polymer and a surfactant are suitably added to thedispersed solution to form a polisher slurry.

In the CMP system, a substrate (for example, a semiconductor wafer) isplaced between polisher pads, which are supported and held by a carrierplate or a pressurization plate and a rotatable polisher table orplaten, and is polished. A fine groove is formed on the surface of thepolisher pad so that even when the substrate is in contact with thesurface of the polisher pad, the polisher slurry can be supplied to thecentral portion of the substrate. The polisher slurry as described aboveis continuously supplied by a pump or the like to the polisher padduring the polishing process.

With such a CMP system, it is possible to remove unevenness on a surfaceof the SiO₂ insulating film and to achieve a flat surface over theentire surface of the semiconductor substrate.

Although a CMP process for an SiO₂ insulating film layer on asemiconductor substrate has been described, the target of CMP processingis not limited to an SiO₂ insulating film layer on a semiconductorsubstrate, and CMP processing may be applied to polishing of, forexample, a wired plate having a predetermined line, an inorganicinsulating film such as glass and silicon nitride, an optical glass suchas a photo mask, a lens, and a prism, an inorganic conductive film suchas ITO (Indium Tin Oxide), an optical integrated circuit, an opticalswitching element, or an optical waveguide which are made of glass and acrystalline material, the end of an optical fiber, an optical singlecrystal such as a scintillator, a solid-state laser single crystal, anLED sapphire substrate for blue laser, a semiconductor single crystalsuch as SiC, GaP, and GaAs, a glass substrate for a magnetic disk, amagnetic head, and the like.

CMP waste water which is discharged in the CMP system contains fineparticles of useful metal compounds such as, f or example, ceria,silica, alumina, and titania particles which were used for the polisherand fine particles of the metal compound which was polished.

The recovery and reuse of useful metal compounds from the fine particlesis also desired.

In recent years, a device has been developed which concentrates the fineparticles of metal compounds contained in the CMP waste water, forexample, using a filtering membrane. In this device of related art, thefine particles in the CMP waste water can be concentrated to 1000mg/L-5000 mg/L. However, it remains difficult to use a concentratehaving such a concentration for reuse of fine particles.

Recently, a filtering device known as a “Slurry Closer” (trade name) hasbeen developed, in which a gel filtering membrane is formed on a surfaceof a filtering membrane having a pore size of 0.25 μm, waste water issucked using a pump from within the filtering membrane, and the membranesurface is cleaned using a supply of generated air bubbles (for example,Japanese Patent Laid-Open Publication No. 2003-135914). With thisfiltering device, the fine particles can be concentrated to, forexample, 10,000 mg/L-300,000 mg/L, and, thus, the concentratingefficiency can be significantly improved.

Improvement of the added value of the highly concentrated particleslurry is desired.

SUMMARY OF THE INVENTION

An advantage of the present invention is that the added value ofparticles recovered from, for example, waste water is increased andreusability is improved.

According to one aspect of the present invention, there is provided ahigh-concentration particle concentrate which is obtained byconcentrating a solution containing particles in a low concentrationhaving a pH adjusted to 3 or greater and 8 or less to a slurrycontaining particles in a high concentration having a concentration of 1weight % to 50 weight %.

The high-concentration particle concentrate can be used in variousfields without further processing. In addition, because the concentrateis highly concentrated, a desired powder can be obtained in a short timewhen the concentrate is dried (moisture is adjusted).

According to another aspect of the present invention, there is provideda method of preparing a high-concentration particle concentrate whereina solution containing particles in a low concentration having a pHadjusted to 3 or greater and 8 or less is concentrated to a slurryhaving the particles in a high concentration having a concentration of 1weight % to 50 weight %.

Similar to the above, the high-concentration particle concentrate can beused in various fields without further processing. In addition, becausethe concentrate is highly concentrated, a desired powder can be obtainedin a short time when the concentrate is dried (moisture is adjusted).

According to another aspect of the present invention, there is provideda method of preparing a powder wherein the slurry containing particlesin a high concentration which is the high-concentration particleconcentrate as above is further processed so that the concentration of aslurry containing the particles is adjusted during re-dispersingaccording to a size of powder to be obtained after drying, and then thedrying process (moisture adjusting process) is applied.

Because the slurry containing particles in high concentration is furtherprocessed such that the concentration of the particle slurry is adjustedduring re-dispersing according to the powder size to be obtained afterdrying, a desired assembly condition, that is, a powder of a desiredsize can be obtained at the later drying process (moisture adjustingprocess).

According to another aspect of the present invention, there is provideda method of preparing a powder wherein the slurry containing particlesin high concentration as above is further processed so that aconcentration of a slurry containing particles is adjusted duringre-dispersing according to a size of powder to be obtained after drying,and then the drying process is applied.

Similar as above, because the slurry containing particles in highconcentration is further processed such that the concentration of theparticle slurry is adjusted during re-dispersing according to the powdersize to be obtained after drying, it is possible to obtain a desiredassembly condition, that is, a powder of desired size during the laterdrying process (moisture adjusting process).

According to another aspect of the present invention, there is provideda method of preparing a powder, wherein a powder is created by vacuumfreeze-drying a slurry having a pH adjusted to 3 or greater and 8 orless and containing particles in a concentration of 20 weight % to 50weight %.

Because a vacuum freeze-dry process is applied using a slurry containingpowder in high concentration, it is possible to significantly reduce thetime for powder drying, and, at the same time, a powder with a higheradded value than slurry can be obtained.

According to another aspect of the present invention, it is preferablethat, in the high-concentration particle concentrate as above, anaverage size of the particles is 50 nm to 500 nm.

According to still another aspect of the present invention, it ispreferable that, in the methods of preparing high-concentration particleconcentrate as above, an average size of the particles is 50 nm to 500nm.

According to another aspect of the present invention, it is preferablethat, in a high-concentration particle concentrate as above, thesolution containing particles in low concentration is CMP waste water.

According to another aspect of the present invention, it is preferablethat, in a method of preparing high-concentration particle concentrateas above, the solution containing particles in low concentration is CMPwaste water.

According to another aspect of the present invention, it is preferablethat, in a high-concentration particle concentrate as above, theparticles include at least SiO₂.

According to another aspect of the present invention, it is preferablethat, in a method of preparing a high-concentration particle concentrateas above, the particles include at least SiO₂.

According to another aspect of the present invention, it is preferablethat, in the method of preparing powder above, the particles include atleast SiO₂.

The above-mentioned compound, SiO₂, is a multipurpose material used invarious fields as a reagent, and its value is enhanced by obtaining thecompound in a powder form.

According to another aspect of the present invention, it is preferablethat, in a high-concentration particle concentrate as above, thesolution containing particles in low concentration is prepared by mixingacidic CMP waste water and basic CMP waste water so that the pH is 3 orgreater and 8 or less.

According to another aspect of the present invention, it is preferablethat, in the method of preparing high-concentration particle concentrateaccording as above, the solution containing particles in lowconcentration is prepared by mixing acidic CMP waste water and basic CMPwaste water so that the pH is 3 or greater and 8 or less.

According to another aspect of the present invention, it is preferablethat, in a high-concentration particle concentrate as above, theparticles include at least one of SiO₂, ceria, alumina, titania, a metalhydroxide, an oxide, ceramic, indium, iron hydroxide, and calciumfluoride.

According to another aspect of the present invention, it is preferablethat, in a method of preparing high-concentration particle concentrateas above, the particles include at least one of SiO₂, ceria, alumina,titania, a metal hydroxide, an oxide, ceramic, indium, iron hydroxide,and calcium fluoride.

According to another aspect of the present invention, it is preferablethat, in a method of preparing powder as above, the particles include atleast one of SiO₂, ceria, alumina, titania, a metalhydroxide, anoxide,ceramic, indium, ironhydroxide, and calcium fluoride.

The above-listed particles are useful metal compounds and recovery andreuse of these compounds is desired.

According to another aspect of the present invention, it is preferablethat, in a method of preparing powder as above, the particles include atleast

one of SiO₂, ceria, alumina, and titania.

For example, it is possible to obtain at least SiO₂, ceria, alumina, andtitania which are included in the CMP waste water and a powder form ofat least SiO₂, ceria, alumina, and titania are useful in a wide varietyof usages and thus having a high added value.

According to another aspect of the present invention, it is preferablethat, in a method of preparing powder as above, the specific surfacearea of the obtained powder is 10 m²/g to 400 m²/g.

It is possible to increase the specific surface area of the obtainedpowder by drying. In addition, it is possible to control the degree ofthe specific surface area of the obtained powder by adjusting the dryingconditions.

According to another aspect of the present invention, it is preferablethat, in a method of preparing powder as above, the average particlesize of the obtained powder is 5 μm to 100 μm.

According to another aspect of the present invention, there is provideda powder which is obtained by any of the methods of preparing powdernoted above.

According to the present invention, it is possible to obtain ahigh-concentration slurry which can be recycled and powder having ahigher added value compared to the high-concentration slurry.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described indetail based on the following drawings, wherein:

FIG. 1 is a diagram for explaining a structure of a powder preparingdevice according to a preferred embodiment of the present invention;

FIG. 2 is a graph showing a relationship between the pH of the solutioncontaining SiO₂ particles in a low concentration and a specific surfacearea of the obtained SiO₂ powder;

FIG. 3 is a schematic diagram showing a surface condition of an SiO₂particle in an acidic solution containing SiO₂ particles in a lowconcentration;

FIG. 4 is a schematic diagram showing a surface condition of an SiO₂particle in a basic solution containing SiO₂ particles in a lowconcentration; and

FIG. 5 is a schematic diagram showing a surface condition of SiO₂particles in a solution containing SiO₂ particles in a low concentrationnear an isoelectric point of SiO₂.

DESCRIPTION OF PREFERRED EMBODIMENT

A preferred embodiment (hereinafter, referred to simply as “embodiment”)of the present invention will now be described.

FIG. 1 shows a structure of a powder preparing device used in a methodof preparing powder according to a preferred embodiment of the presentinvention. As shown in FIG. 1, the powder preparing device according tothe present embodiment can be viewed as a combination of a filteringdevice 10 for treating CMP (Chemical Mechanical Polishing) waste wateras described and a vacuum freeze-drying device 20 for applying a vacuumfreeze-dry process to a slurry which is concentrated to a concentrationof, for example, 1 weight %-50 weight %, more preferably, 20 weight % to50 weight % by the filtering device 10. As described above, a membranemodule 12 is placed within the filtering device 10 in which at least onegel filtering membrane is provided in which a gal layer is formed on asurface of a filtering membrane having a pore size of 0.25 μm. A pump 14sucks waste water from the gel filtering membrane of the membrane module12. AS the filtering device 10, for example, it is preferable to use adevice such as the “Slurry Closer” (trade name) manufactured by SanyoAqua Technology Co., Ltd., in which air bubbles are lightly generated ona surface of the membrane.

Examples of the particles within the CMP waste water include, forexample, a polisher used in the CMP system such as cerium oxide (ceria;CeO₂), a silica particle, an alumina particle, a titania (titaniumoxide; TiO₂) particle. Although these particles of the polisher are themain composition of the CMP waste water, the CMP waste water alsocontains, for example, an SiO₂ particle which is a polishing waste ofthe SiO₂ insulating film layer of the semiconductor substrate, a metalhydroxide, anoxide, ceramic, indium, ironhydroxide, and calciumfluoride.

In particular, the CMP waste water which is generated when an SiO₂insulating film layer of a semiconductor substrate is polished using apolisher made of a silica particle is known as a “basic CMP waste water”because the pH of the CMP waste water is around 10. In this basic CMPwaste water, almost 100% of the inorganic particles within the CMP wastewater is SiO₂. In addition, a percentage of the basic CMP waste wateramong all CMP waste water is high. The CMP waste water which contains alarge amount of metals other than SiO₂, which is generated duringpolishing in the semiconductor field or other fields, are referred to as“acidic CMP waste water” because the pH is around 2.

An average size of the particle in such a CMP waste water is 50 nm to500 nm, more preferably 50 nm to 200 nm, and is in a range of size forparticles which are called “colloids”. A normal average particle size isaround 100 nm. For example, when the particle is SiO₂, the particle isin the state of colloidal silica.

A pH of a solution containing particles in a low concentration to besupplied to the filtering device 10, in particular, the CMP waste wateris preferably adjusted to 3 or greater and 8 or less. As shown in FIG.2, in a solution containing particles in a low concentration in which100% of the inorganic particles is SiO₂, a specific surface area ismaximum around a pH of 4, and, thus, it can be seen that this pH is anisoelectric point. In addition, it can be seen that the pH is preferably8 or less in order for the specific surface area of the SiO₂ powderafter concentration and vacuum dry-freezing processes by the powderpreparing device as described above to be 130 m²/g or greater, which isa specific surface area sufficient for allowing use as a highfunctionality particle. On the other hand, a pH of less than 3 for thesolution containing particles in low concentration is not preferablebecause, not only the specific surface area is reduced, but also, thereis a possibility that corrosion may occur during a concentrating processin the filtering device 10.

A relationship between a pH of the solution containing particles in lowconcentration and the specific surface area of the powder after theconcentration and vacuum dry-freezing processes will be described inmore detail referring to FIGS. 3-5 and an example solution containingparticles in low concentration containing only SiO₂ particles.

As shown in FIG. 3, when the pH of the solution containing SiO₂particles is lower than the isoelectric point pH of 4, that is, when thepH is less than 4 (this solution is hereinafter referred to as an“acidic solution”), the interparticle spacing is increased because of arepulsive force between particles caused by charging of the surface ofthe particles, and, as a result, the particles tend to not aggregate andthe specific surface area tends to be reduced. Similarly, as shown inFIG. 4, when the pH of the solution containing SiO₂ particles is greaterthan the isoelectric point pH of 4, that is, when the pH exceeds 4 (thissolution is hereinafter referred to as a “basic solution”), theinterparticle spacing is increased because of a repulsive force betweenparticles caused by charging of the surface of the particles, and, as aresult, the particles tend not to aggregate and the specific surfacearea tends to be reduced. When, on the other hand, the pH of thesolution containing SiO₂ particles is at the isoelectric point pH of 4as shown in FIG. 5 (this solution is hereinafter referred to as a“neutral solution”), the particle surface is not charged, and thus, norepulsive force is created between particles. Therefore, theinterparticle spacing is decreased, the particles tend to aggregate,and, as a result, the specific surface area is increased.

Methods suitable for adjusting the pH of the solution containingparticles in a low concentration, include (a) to adjust the pH to avalue of 3 or greater and 8 or less by suitably mixing the acidic CMPwaste water and the basic CMP waste water, and (b) to prepare thesolution containing particles in low concentration having the pHadjusted by adding a pH adjusting agent to the acidic and/or basic CMPwaste water. In the present example, as the pH adjusting agent, it ispossible to use, for example, potassium hydroxide and ammoniumhydroxide. Alternatively, it is also possible (c) to supply, to thefiltering device 10, a solution containing particles in a lowconcentration in which the pH is not adjusted and to suitably adjust thepH within the filtering device 10 using the pH adjusting agent.Moreover, it is also possible (d) to supply, to the filtering device 10,a solution containing particles in a low concentration in which the pHis not adjusted, monitor the pH within the filtering device 10, andcomplete the concentrating process when the pH exceeds the range of 3 orgreater and 8 or less, to obtain a slurry containing particles in a highconcentration.

In the present embodiment, it is preferable to adjust the pH of thebasic CMP waste water having a main composition of SiO₂ particles as theCMP waste water and to apply the concentrating and vacuum dry-freezingprocesses. Because it is thereby possible to obtain a pure SiO₂ powderhaving a high purity, it is possible to reuse the powder as a powderwith a high added value.

It is also preferable to concentrate, using the filtering device 10, thesolution containing particles in a low concentration to form a slurryhaving a concentration of 1 weight %-50 weight %, and more preferably,20 weight %-50 weight %. In particular, by applying the vacuumdry-freezing process to the slurry concentrated to a high concentrationof 20 weight %-50 weight %, it is possible to significantly shorten thedrying time. In addition, it is possible to maintain uniform particlesize for the obtained powder.

In the present embodiment, it is preferable to use a vacuumfreeze-drying device 20 as a drying device for drying the slurrycontaining particles in a high concentration. The conditions for vacuumfreeze-drying are suitably selected according to the concentration ofthe slurry containing particles in a high concentration. For example, itis preferable that the temperature is −70° C. to 0° C., more preferably−60° C. to −5° C., and more preferably −10° C. to −5° C. (freezingtemperature), and the degree of vacuum is 2 mmHg-5 mmHg (2.7 hPa(N/m²)-6.7 hPa (N/m²)). It is possible to use, for example, theTFD-550-8SP device manufactured by Takara Seisakusho as the vacuumfreeze-drying device.

According to experiments by the present inventors, when a freeze-dryprocess was applied to a slurry which had been concentrated to 30 weight% by the filtering device 10 and had an average particle size of 18.5μm, no grinding was necessary and the average size of the powder was59.0 μm. On the other hand, when a heat drying process was applied tothe same slurry, the particles became sintered, and therefore, wereground in a mortar. The average size of the ground powder was 120.8 μm.From these results it can be seen that, to obtain a powder with a smallparticle size, it is preferable to employ a vacuum freeze-dry process.

The high-concentration slurry which is a high-concentration particleconcentrate obtained by the filtering device 10 can be used without anyfurther processing as, for example, a glaze of crockery, a cosmeticproduct, or a polisher. In addition, it is also possible to suitably addan additive to the high-concentration particle concentrate according todesired use.

The average size of a powder obtained by applying the vacuum freeze-dryprocess under the above-described conditions using the powder preparingdevice was 5 μm-100 μm. For example, when the powder is SiO₂, a powderhaving an average size of approximately 30 μm, that is, a fumed silica,is obtained.

It is desirable to further adjust the concentration of the particleslurry in the slurry containing particles in high concentration obtainedby the filtering device 10 during re-distribution according to powdersize to be obtained after the drying process and to apply the dryingprocess.

In the drying process, for example, in the vacuum freeze-drying process,it is possible to control the particle size of the dried powder bysuitably adjusting the state of vacuum and drying temperature. In thismanner, it is possible to refine a powder having a desired particle sizeaccording to the intended use of the obtained powder.

The specific surface area of the powder obtained in the drying processis 10 m²/g to 400 m²/g.

It is possible to increase the specific surface area of the obtainedpowder by applying a drying process. In addition, it is possible tocontrol a degree of the specific surface area of the powder to beobtained by adjusting the drying conditions.

The powder obtained by the powder preparing device and method ofpreparing powder as described above can be used, for example, as aporous material, a cosmetic product, an adsorbent, ceramic, a filteringassisting agent, a hydrophilic processing agent, a filler for analysisequipment (for example, filler for gas chromatography or the like), andan additive of toner for printing.

The use of the high-concentration slurry may be suitably selectedaccording to the type of powder contained in the slurry and may include,for example, a crockery or ceramic glaze, a cosmetic product, or apolisher.

In addition, the powder may be used in any field as long as the powderobtained by drying a CMP waste water can be used, and, for example, maybe preferably used as a porous material, a cosmetic product, anadsorbent, ceramic, a filter assisting agent, a hydrophilic processingagent, a filler of an analysis equipment (for example, filler in gaschromatography or the like), or an additive to a toner used forprinting.

1. A high-concentration particle concentrate obtained by concentrating asolution containing particles in a low concentration having a pHadjusted to 3 or greater and 8 or less to a slurry containing particlesin a high concentration having a concentration of 1 weight % to 50weight %.
 2. A method of preparing a high-concentration particleconcentrate wherein a solution containing particles in a lowconcentration having a pH adjusted to 3 or greater and 8 or less isconcentrated to form a slurry containing particles in a highconcentration having a concentration of 1 weight % to 50 weight %.
 3. Amethod of preparing a powder, wherein the slurry containing particles inhigh concentration which is the high-concentration particle concentrateaccording to claim 1 is further processed so that a concentration of aslurry containing particles is adjusted during re-dispersing accordingto a size of powder to be obtained after the drying process, and thenthe drying process is applied.
 4. A method of preparing a powder,wherein the slurry containing particles in high concentration accordingto claim 2 is further processed so that a concentration of a slurrycontaining particles is adjusted during re-dispersing according to asize of powder to be obtained after drying, and then the drying processis applied.
 5. A method of preparing powder, wherein a powder is createdby vacuum freeze-drying a slurry having a pH adjusted to 3 or greaterand 8 or less and containing particles in a concentration of 20 weight %to 50 weight %.
 6. A high-concentration particle concentrate accordingto claim 1, wherein the average particle sizer of the particleconcentrate is 50 nm to 500 nm.
 7. A method of preparinghigh-concentration particle concentrate according to claim 2, wherein anaverage particle size of the particle concentrate is 50 nm to 500 nm. 8.A method of preparing powder according to claim 3, wherein an averageparticle size of the particle concentrate is 50 nm to 500 nm.
 9. Amethod of preparing powder according to claim 4, wherein an averageparticle size of the particle concentrate is 50 nm to 500 nm.
 10. Amethod of preparing powder according to claim 5, wherein an average sizeof the particles in a slurry is 50 nm to 500 nm.
 11. Ahigh-concentration particle concentrate according to claim 1, whereinthe solution containing particles in low concentration is CMP wastewater.
 12. A method of preparing a high-concentration particleconcentrate according to claim 2, wherein the solution containingparticles in low concentration is CMP waste water.
 13. Ahigh-concentration particle concentrate according to claim 1, whereinthe particles include at least SiO₂.
 14. A method of preparinghigh-concentration particle concentrate according to claim 2, whereinthe particles include at least SiO₂.
 15. A method of preparing powderaccording to claim 3, wherein the particles include at least SiO₂.
 16. Amethod of preparing powder according to claim 4, wherein the particlesinclude at least SiO₂.
 17. A method of preparing powder according toclaim 5, wherein the particles include at least SiO₂.
 18. Ahigh-concentration particle concentrate according to claim 1, whereinthe solution containing particles in low concentration is prepared bymixing acidic CMP waste water and basic CMP waste water so that the pHis 3 or greater and 8 or less.
 19. A method of preparinghigh-concentration particle concentrate according to claim 2, whereinthe solution containing particles in low concentration is prepared bymixing acidic CMP waste water and basic CMP waste water so that the pHis 3 or greater and 8 or less.
 20. A high-concentration particleconcentrate according to claim 1, wherein the particles include at leastone of SiO₂, ceria, alumina, titania, a metal hydroxide, an oxide,ceramic, indium, iron hydroxide, and calcium fluoride.
 21. A method ofpreparing high-concentration particle concentrate according to claim 2,wherein the particles include at least one of SiO₂, ceria, alumina,titania, a metal hydroxide, anoxide, ceramic, indium, iron hydroxide,and calcium fluoride.
 22. A method of preparing powder according toclaim 3, wherein the particles include at least one of SiO₂, ceria,alumina, titania, a metal hydroxide, anoxide, ceramic, indium, ironhydroxide, and calcium fluoride.
 23. A method of preparing powderaccording to claim 4, wherein the particles include at least one ofSiO₂, ceria, alumina, titania, a metal hydroxide, anoxide, ceramic,indium, iron hydroxide, and calcium fluoride.
 24. A method of preparingpowder according to claim 5, wherein the particles include at least oneof SiO₂, ceria, alumina, and titania.
 25. A method of preparing powderaccording to claim 3, wherein the specific surface area of the obtainedpowder is 10 m²/g to 400 m²/g.
 26. A method of preparing powderaccording to claim 4, wherein the specific surface area of the obtainedpowder is 10 m²/g to 400 m²/g.
 27. A method of preparing powderaccording to claim 5, wherein the specific surface area of the obtainedpowder is 10 m²/g to 400 m²/g.
 28. A powder obtained by a method ofpreparing powder according to claim 5, wherein an average size of theobtained powder is 5 μm to 100 μm.
 29. A glaze containing ahigh-concentration particle concentrate according to claim
 1. 30. Apolisher containing a high-concentration particulate concentrateaccording to claim
 1. 31. A cosmetic product containing ahigh-concentration particle concentrate according to claim
 1. 32. Apowder obtained by the method of preparing powder according to claim 3.33. A powder obtained by the method of preparing powder according toclaim
 4. 34. A porous material made of a powder obtained by the methodof preparing powder according to claim
 5. 35. A cosmetic productcontaining a powder obtained by the method of preparing powder accordingto claim
 5. 36. An adsorbent containing a powder obtained by a method ofpreparing powder according to claim
 5. 37. A ceramic containing a powderobtained by the method of preparing powder according to claim
 5. 38. Afiltering assisting agent containing a powder obtained by the method ofpreparing powder according to claim
 5. 39. A hydrophilic processingagent containing a powder obtained by the method of preparing powderaccording to claim
 5. 40. A filler for an analysis equipment, the fillercontaining a powder obtained by the method of preparing powder accordingto claim
 5. 41. An additive of a toner for printing, the additivecontaining a powder obtained by the method of preparing powder accordingto claim
 5. 42. A porous material made of a powder obtained by themethod of preparing powder according to claim
 3. 43. A cosmetic productcontaining a powder obtained by the method of preparing powder accordingto claim
 3. 44. An adsorbent containing a powder obtained by the methodof preparing powder according to claim
 3. 45. A ceramic containing apowder obtained by the method of preparing powder according to claim 3.46. A filtering assisting agent containing a powder obtained by themethod of preparing powder according to claim
 3. 47. A hydrophilicprocessing agent containing a powder obtained by the method of preparingpowder according to claim
 3. 48. A filler for an analysis equipment, thefiller containing a powder obtained by the method of preparing powderaccording to claim
 3. 49. An additive of a toner for printing, theadditive containing a powder obtained by the method of preparing powderaccording to claim
 3. 50. A porous material made of a powder obtained bythe method of preparing powder according to claim
 4. 51. A cosmeticproduct containing a powder obtained by the method of preparing powderaccording to claim
 4. 52. An adsorbent containing a powder obtained bythe method of preparing powder according to claim
 4. 53. A ceramiccontaining powder obtained by the method of preparing powder accordingto claim
 4. 54. A filtering assisting agent containing a powder obtainedby the method of preparing powder according to claim
 4. 55. Ahydrophilic processing agent containing a powder obtained by the methodof preparing powder according to claim
 4. 56. A filler for an analysisequipment, the filler containing a powder obtained by the method ofpreparing powder according to claim
 4. 57. An additive of a toner forprinting, the additive containing a powder obtained by the method ofpreparing powder according to claim 4.